J/ApJ/895/71ivo://CDS.VizieR/J/ApJ/895/71doi:10.26093/cds/vizier.18950071CDSElmegreen B.G.Elmegreen D.M.2022-03-10T07:10:13Z2021-10-06T12:07:18ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesstar-forming-regionsinfrared-photometryTo study the vertical distribution of the earliest stages of star formation in galaxies, three edge-on spirals, NGC891, NGC3628, and IC5052, observed by the Spitzer Space Telescope InfraRed Array Camera (IRAC) were examined for compact 8{mu}m cores using an unsharp mask technique; 173, 267, and 60 cores were distinguished, respectively. Color-color distributions suggest a mixture of polycyclic aromatic hydrocarbons and highly extincted photospheric emission from young stars. The average V-band extinction is ~20mag, equally divided between foreground and core. IRAC magnitudes for the clumps are converted to stellar masses assuming an age of 1Myr, which is about equal to the ratio of the total core mass to the star formation rate in each galaxy. The extinction and stellar mass suggest an intrinsic core radius of ~18pc for 5% star formation efficiency. The half-thickness of the disk of 8{mu}m cores is 105pc for NGC891 and 74pc for IC5052, varying with radius by a factor of ~2. For NGC3628, which is interacting, the half-thickness is 438pc, but even with this interaction, the 8{mu}m disk is remarkably flat, suggesting vertical stability. Small-scale structures like shingles or spirals are seen in the core positions. Very few of the 8{mu}m cores have optical counterparts.2020ApJ...895...71Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/895/71CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/74 : Atlas of Peculiar Galaxies (Arp 1966)J/ApJ/642/158 : IRAC flux densities in IC2163 and NGC2207 (Elmegreen+, 2006)J/ApJ/669/493 : Spitzer/Chandra YSOs in Serpens cloud core (Winston+, 2007)J/ApJ/688/237 : Disk corrugations in IC 2233 (Matthews+, 2008)J/AJ/135/693 : X-ray and IR sources in RCW 108 (Wolk+, 2008)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/AJ/140/266 : NGC 1333 X-ray luminous YSOs properties (Winston+, 2010)J/A+A/527/A109 : Dust and PAH emission SEDs of disk galaxies (Popescu+, 2011)J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)J/AJ/146/86 : Cosmicflows-2 catalog (Tully+, 2013)J/A+A/565/A4 : NGC 891 70-500um images (Hughes+, 2014)J/ApJ/862/25 : H{alpha}&UV emission scale heights for edge-on gal. (Jo+,2018)J/ApJS/245/14 : 8um cores in spiral arms of nearby galaxies (Elmegreen+, 2019)J/ApJ/882/5 : ALMA data 5 luminous & ultraluminous IR gal. (Wilson+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/895/71https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/895/71http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/895/71https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/895/71https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/895/71http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/895/71GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/895/71/table5 (8um Cores in NGC 891, NGC 3628 and IC 5052)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/895/71/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/895/71/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/895/71/table5?GETtext/xml+votable180.050000true35.682916742.42858330.0055555555555555566/2409 28184 453052.0616683193919197e-20 6.185923063528282e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/895/71?format=asciiInfrareddefaultJ/ApJ/895/71/table58um Cores in NGC 891, NGC 3628 and IC 5052recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDGalaxy identificationmeta.id.parentcharRAJ2000[2/20] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainmag3.6[13.2/20.3]? Spitzer/IRAC 3.6micron band magnitude (1)magphot.flux.density;em.IR.3-4umfloatnullablee_mag3.6[0.1/3]? Uncertainty in mag3.6magstat.errorfloatnullablemag4.5[12.3/19.7]? Spitzer/IRAC 4.5 micron band magnitude (1)magphot.flux.density;em.IRfloatnullablee_mag4.5[0.1/3]? Uncertainty in mag4.5magstat.errorfloatnullablemag5.8[11.1/19]? Spitzer/IRAC 5.8micron band magnitude (1)magphot.flux.density;em.IR.4-8umfloatnullablee_mag5.8[0.09/3]? Uncertainty in mag5.8magstat.errorfloatnullablemag8.0[9.3/17.8] Spitzer/IRAC 8.0micron band magnitude (1)magphot.flux.density;em.IR.8-15umfloate_mag8.0[0.06/3] Uncertainty in mag8.0magstat.errorfloat3.6-4.5[-1.2/2.2]? Color, [3.6]-[4.5]magphot.color;em.IR;em.IRfloatnullable4.5-5.8[-0.7/3.93]? Color, [4.5]-[5.8]magphot.color;em.IR;em.IRfloatnullable5.8-8.0[0.51/3.08]? Color, [5.8]-[8.0]magphot.color;em.IR;em.IRfloatnullable